1. Field of the Invention
The present invention relates to a voltage-detecting circuit, and more particularly, to a method for detecting a power status of a battery with the voltage-detecting circuit, which comprises a comparator, resistors, and switches.
2. Description of the Prior Art
In recent years, the dramatic development of communications technology has brought widespread use of cellular phones. In general, a cellular phone uses a chargeable battery as a power source. Therefore, a user of the cellular phone has to observe the power status of the battery from time to time, facilitated by a voltage-detecting circuit of the cellular phone, to know how long the cellular phone can be used.
According to the prior art, a cellular phone comprises an 8-bit A/D converter to detect power status of a battery, the A/D converter converting an analog power status to a digital representation of the power status. The cellular phone is therefore capable of detecting the power status of the battery by detecting voltages at a variety of pins of the A/D converter.
As far as a method for detecting the power status of the battery is concerned, an A/D converter is simply unnecessary because a user of a cellular phone only cares how long the cellular phone can likely be used. Such a dedicate A/D converter capable of detecting a battery status with up to 256 (28) power segments is unnecessarily precise and costly for a cellular phone.